From 400e5bd8ad2b2daef411e5530b6fda6158672829 Mon Sep 17 00:00:00 2001
From: Tyge Løvset <tylo@norceresearch.no>
Date: Mon, 27 Feb 2023 16:37:13 +0100
Subject: Enhanced c_with and c_scope macros. Improved coroutine.h and example.

---
 include/stc/algo/coroutine.h | 22 ++++++++++++++++------
 include/stc/ccommon.h        | 10 ++++++----
 2 files changed, 22 insertions(+), 10 deletions(-)

(limited to 'include/stc')

diff --git a/include/stc/algo/coroutine.h b/include/stc/algo/coroutine.h
index da15aa5b..150fa9ec 100644
--- a/include/stc/algo/coroutine.h
+++ b/include/stc/algo/coroutine.h
@@ -60,13 +60,20 @@ int main(void) {
 */
 #include <stc/ccommon.h>
 
+enum {
+    cco_state_final = -1,
+    cco_state_done = -2,
+    cco_state_illegal = -3,
+};
+
 #define cco_begin(ctx) \
     int *_state = &(ctx)->cco_state; \
     switch (*_state) { \
-        case 0:
+        case 0: \
+        case cco_state_done:;
 
 #define cco_end(retval) \
-        *_state = 0; break; \
+        *_state = cco_state_done; break; \
         default: assert(!"missing cco_final: or illegal state"); \
     } \
     return retval
@@ -77,15 +84,18 @@ int main(void) {
         case __LINE__:; \
     } while (0)
 
-#define cco_yield_coroutine(ctx, corocall, retval) \
+#define cco_coroutine(corocall, ctx, retval) \
     do { \
         *_state = __LINE__; \
         c_PASTE(cco, __LINE__): corocall; return retval; \
-        case __LINE__:; if (cco_alive(ctx)) goto c_PASTE(cco, __LINE__); \
+        case __LINE__: if (cco_alive(ctx)) goto c_PASTE(cco, __LINE__); \
     } while (0)
 
-#define cco_final case -1
+#define cco_final case cco_state_final
+#define cco_stop(ctx) (((ctx)->cco_state = cco_alive(ctx) ? \
+                       cco_state_final : cco_state_illegal), ctx)
+#define cco_reset(ctx) ((ctx)->cco_state = 0)
+#define cco_done(ctx) ((ctx)->cco_state == cco_state_done)
 #define cco_alive(ctx) ((ctx)->cco_state > 0)
-#define cco_stop(ctx) ((ctx)->cco_state = cco_alive(ctx) ? -1 : -2), ctx)
 
 #endif
diff --git a/include/stc/ccommon.h b/include/stc/ccommon.h
index 711a9c6d..d163b4ab 100644
--- a/include/stc/ccommon.h
+++ b/include/stc/ccommon.h
@@ -209,10 +209,12 @@ STC_INLINE char* cstrnstrn(const char *str, const char *needle,
          ; it.index < it.size; ++it.ref, ++it.index)
 #endif
 #define c_with(...) c_MACRO_OVERLOAD(c_with, __VA_ARGS__)
-#define c_with_2(declvar, drop) for (declvar, **_c_i = NULL; !_c_i; ++_c_i, drop)
-#define c_with_3(declvar, pred, drop) for (declvar, **_c_i = NULL; !_c_i && (pred); ++_c_i, drop)
-#define c_scope(init, drop) for (int _c_i = (init, 1); _c_i; --_c_i, drop)
-#define c_defer(...) for (int _c_i = 1; _c_i; --_c_i, __VA_ARGS__)
+#define c_with_2(declvar, drop) for (declvar, *_i, **_ip = &_i; _ip; _ip = 0, drop)
+#define c_with_3(declvar, pred, drop) for (declvar, *_i, **_ip = &_i; _ip && (pred); _ip = 0, drop)
+#define c_scope(...) c_MACRO_OVERLOAD(c_scope, __VA_ARGS__)
+#define c_scope_2(init, drop) for (int _i = (init, 1); _i; _i = 0, drop)
+#define c_scope_3(init, pred, drop) for (int _i = (init, 1); _i && (pred); _i = 0, drop)
+#define c_defer(...) for (int _i = 1; _i; _i = 0, __VA_ARGS__)
 
 #define c_auto(...) c_MACRO_OVERLOAD(c_auto, __VA_ARGS__)
 #define c_auto_2(C, a) \
-- 
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